#include<stdio.h>


int Sum(int n)
{
int flag = 1;

if(flag == 1) printf("haha\n");
else printf("hehe\n");

int i = 1;
int sum =0;
for(;i< n; i++ )
{
  sum += i;
}

  return sum;

}


int main()
{
  printf("hello world\n");

  int result = Sum  (100);
  printf("result = %d\n",result);
  return 0;
}
